Distance comparator gauge



May 13, 1952 D. J. BAKER DISTANCE COMPARATOR GAUGE 2 SHEETS-SHEET 1 Filed- Sept. 28, 1944 DONALD J. BEEF-R y 1952 0. J, BAKER 2,596,519

DISTANCE COMPARATOR GAUGE iled Sept. 28, 1944 a 2 SHEETS -SHEET 2 9 7. Q 6 ,7 Y m. '3. 5' 5 v '70 4 o #6 O O lb H" 19 10 196' if? 170' 5 b 16 v I 19 619: 1a

Patented May 13, 1952 2,596,513 DISINQE COMPARAIOR= GAUGE; assault: new Log Aae e awia aeplieati a fiwe fli l l": ewe;-

This invention relates .130 measurlngl-gau fis fi d in, particular. to gauges; having uopposedrcpntacts ion-measuring distance.

My. inventionis especially useful-in the vtype,

oiggaugeaemployed for; testing the? dimensions of an qbjeelnfermthempurpose .of. determining whether 1 n tthe dimension is larger or, smaller than aldesixeghamounn An objeetloiltheinvention-is-tqprqziueeameasmfi-nge gauge; of a simple. and rugged eon st metion hutsh aving high sensitivity.

Ar, further object; 01 the inyentipnis t devise al e rin lgaugerin which themensi i i y of E he augemaylbeyariedl S i l another i\e c1:=. .is,toapxt iden r measuri gauge capable,bofrcoveringa widekrange of;meas;-

Eigurevhis;amseqtienalmiew qf Figurefi taken alongthedine l-:43; an

Figure- 4 a seetiqnal view fi l sm'e31 mm along lime-i;

Referrin -tame @rawing ndicatesihe m i casing; frame of: the au ewh ch sl ormedw elongated sleev ,wh qhs s l t a on P rt: of ite en th hawn eti nd-melee an ad: justable rod positioned within the; sleevel and heva ne raq el; mo nfi d; h nd tlgereof which carries; ope 0f the. apposed. con- .wg r 1. ;m jeymed h i The er d of tlg e red. 2 ha a $191: 2a. formed n a wa I leeve '5 me a h ea e n? n-witntl nf po e s re@ 156: he sleeve This WW ermi e h r iu llymi tbin -s leeve I; an d tto beeclampedwi n any a edie sili e For 1 2 namqs w meduc n axi l adjustment thes ee l mte m n e eeve band 7 Clalmg. (01. 33 -147) material is inteliposed betvveelri" thejhead'fifft we screw l0 and, lack? Washer. 9Q 'Thel'arrahlgemeiit of the lpck washei a. i s'jnioif'e cmarmmustrateq inflig u re- 5, ar id thepuipdslembithilcbnstl is to secure the. sleevfe"Rte'thefsliarikbfl on a shoulder in sleeve I to acts against the lower face of the flange I la tending to move the plunger II away from the anvil 3a.

The arrangement for operating plunger II is contained within an extension housing carried by boss I b. The inner space of the extension housing is cylindrical in form, one-half of the cylindrical wall being formed "in the boss lb, while the other half of the cylindrical wall is formed by a removable wall portion Ic, see Figure 3. A pair of circular end walls Id and le complete the extension housing, see Figures 2 and 4, The arrangement for operating plunger II embodies a circular cam I2 which is mounted for rotation within the extension housing, the outer edge of the cam serving as an adjustable stop for plunger II. The arrangement for mounting the cam I2 is illustrated in detail in Figure 4. The cam is mounted for rotation about an axis which is eccentric with respect to its own axis, the mounting arrangement permitting adjustment of the amount of eccentricity. As shown in Figure 4, cam I2 is adjustably clamped to one face of mounting disk I3 which has a supporting shaft I311, one end of which is pivotally supported in suitable ball bearings mounted in the end of a threaded plug Ill carried by end-wall Id, and the opposite end is pivotally mounted in suitable ball bearings carried by the inner end of plug I5 mounted in end-wall Ie. For the purpose of avoiding any play or lost motion in cam I2, I prefer to support shaft lt a by pivot or conical bearings of the type shown in the drawing, but other constructions may be employed. Plug I5 is adjusted to remove all play in the bearings and is then looked in position by lock nut I5a. Cam I2 has a central opening formed at the center thereof which receives the mounted shaft I311, with considerable clearance as shown in Figures 3 and 4. The cam I2 is clamped to the diskI3 by suitable mounting screws I6 (Figure 3) which extend from mounting disk I3 and engage a clamp ring Ifia on the other side of cam I2. The clamping screws I6 pass through holes formed in cam I2 which provide considerable clearance around the clamping screws as shown in Figure 3. This permits adjustment of the amount of eccentricity between the center of cam I2 and the axis of rotation of disk I3. A pair of guide pins Ila and Ill) are secured to the cam I2 at diametrically opposite points. The pins extend parallel with the axis of disk I3 and are positioned within radial slots formed in the outer edge of disk I3 to prevent relative displacement of cam I2 with respect to the disk I3 atright angles to the plane of the two pins but permitting adjustment of the cam with respect to the disk in a direction parallel with the plane of the two pins. As will be seen in Figure 4, pin I'Ib extends through slot Ie' formed in end wall Ie and is connected to a friction clutch embodied in an operating knob to be described hereinafter. The slot Ie is arcuate in shape as shown in dotted lines in Figure 3 to permit rotation of cam I2 substantially through one-half revolution. The cam rotates in a clockwise direction from the position as shown in Figure 3. Pin I?!) may be a short pinlike Na, and a separate pin or arm may be secured to the disk I3 for rotating cam I2 from the friction clutch.

The arrangement. for operating the cam is shown in detail in Figure 4. The threaded plug I5 is provided with a reduced stem I5b on which is supported an operating knob I8' which embodies a friction clutch construction somewhat like that shown in Figure 3 but having a some what different mode of operation. This arrangement includes a sleeve 1' surrounding stem I5b and having a radial flange 'I'a. The clutch also embodies a lock washer 9' having inwardly extending tongues which are positioned in a slot formed in the end of the sleeve-1' in the same manner as in Figure 3, but the tongues are not locked to stem I5b. Washer 9 is held in position by screw II! with a fiber washer IIla interposed, but the screw III does not clamp the sleeve I to stem I5b, the sleeve 1' being free to rotate on the stem. In the construction of Figure 4 a pair of fiber washers 8'a are interposed bea tween the knob I 8 and the flange Va and a clutch plate 80 is interposed between these two fiber washers. ,Clutch plate 80 has an extension with I8 causes rotation of clutch disk 80 through frictional contact with disks 8'a, whereby cam I2 is rotated by pin IIb. If resistance to movement of the pin I'Ib exceeds a certain limit, the

clutch begins to slip and cam I2 will not rotate. V

For the purpose of indicating the amount of rotation of the cam I2, a graduated scale III of arcuate shape is mounted to move with the cam, and the preferred arrangement is to mount the scale to cover a portion of the peripheral edge of cam I2 as shown in Figure 3, but the scale may be mounted on disk I3 if desired. The scale is secured in position by means of a radial flange I9a which extends into a radial slot formed in disk I3 and is clamped to one face of the cam I2 by means of a screw I9b passing through an elongated aperture I9c formed in the flange Illa. Elongated slot I permits adjustment of the scale around the cam I2 to a limited extent. The removable wall portion Ic of the eccentric housing is provided with a viewing window 25 at the upper portion thereof for the purpose of viewing the scale I9. The window is covered by a transparent panel such as glass or other material having an index line 29a formed thereon as shown in Figure 1a. The scale I9 is preferably provided with double graduations beginning with the zero at the center and extending in opposite directions. One set of graduations is printed in red while the other may be printed in a contrasting color such as black or blue. Instead of having graduations on the scale, it may have a center line with the word Go printed on one side and the word No-go printed on the other side.

It will be understood that the cam disk I2 is formed of hardened steel or other suitable material, and the peripheral face thereof is accurately ground to circular shape over the portion which serves as a stop for the plunger II, that is, it is ground to have a constant. radius over the working range of the peripheral edge. The cam I2 is mountedon disk I3 so that it is eccentric with respect to the rotary axis of the mounting disk I3, and the sensitivity of the gauge is dependent upon the amount of eccentricity. That is if the gauge is to indicate small differences in a dimension, then the eccentricity should be small, whereas if the gauge is to allow for a considerable variation in dimension, the eccen tricity may be larger. If the cam disk I2 is displaced one-thousandth of an inch with respect to the axis of disk I3, plunger II will be moved through two-thousandths of an inch when disk I2 is rotated through 180. Accordingly, the graduations on scale l9 can be laid out to represent movements equal to twice the amount of eccentricity of disk I2 with respect to disk [3. With a displacement of one-thousandth of an inch, the two extreme positions of the scale 19 would represent a diilerence in measurement of two one-thousandths of an inch, and the two end portions of the scale may be subdivided into ten divisions so that each division would represent one ten-thousandth of an inch.

In the use of my gauge, it is first set for testing of a definite distance or dimension by placing a standard gauge block of the correct dimension between the anvil 3a and the plunger II. Cam I2 is then moved until the scale I9 is in the zero position; bolt 4 is then loosened and knob 8 is adjusted to clamp the gauge block between the two contact members. As soon as the friction clutch in knob 8 begins to slip, bolt 4 is tightened and the gauge is properly set for use. In using the gauge for checking the dimensions of articles, cam 12 is rotated in a direction to separate the contacts to the greatest extent possible, the article is inserted between the contacts and cam I2 is then rotated to bring plunger H into engagement with the article. The position at which the cam l2 stops, after the friction clutch in knob 18 begins to slip, will be indicated by dial I9 and will provide an indication of the dimension of the article by comparison with the standard gauge block.

The gauge as described above may be held in the hand during use, or if desired, it may be used as a bench gauge by providing a suitable base 22 which is removably secured to the gauge by a suitable screw 22a, see Figure 1. By forming the anvil 3a so that it is removable from its socket, anvils of difierent lengths may be inserted and thereby greatly extend the range of usefulness of the gauge for a given length of slot 20: in rod 2, or the same result may be obtained by providing a series of anvil supporting rods of different lengths which may be substituted for the rod 2 as required. For the purpose of measuring threaded rods or shafts, the anvil and plunger may be provided with jaws having thread engaging points or teeth formed on the opposing faces thereof, for the accurate measurement of threaded pieces without unnecessary wear on the threads of the pieces being measured, thus providing a non-wearing Go and No-go thread gauge.

It will be obvious that the construction shown and described herein may be varied in many ways without departing from the principle of the invention.

I claim:

1. In a measuring gauge, the combination of a housing, a disk rotatably supported within said housing and having a flat side face normal to its axis of rotation, a circular cam adjustably secured to said flat face of said disk, a movable plunger carried by said housing and positioned to move radially of said cam, biasing means for urging said plunger into engagement with the peripheral edge of said earn, a rotary knob mounted on the outside of said housing in axial alignment with said rotary disk, and connecting means passing from said rotary knob through an arcuate slot formed in said housing at a fixed distance from, the axis of said disk and serving to rotate said cam by said knob.

2. A combination according to claim 1 wherein said knob embodies a friction clutch interposed in the driving connection between said knob and said cam.

3. In a measuring gauge, the combination of a movable plunger forming a contact element, biasing means for moving said plunger in one direction, a circular cam positioned so the edge thereof serves as a stop for said plunger, means mounting said cam for rotation about an axis eccentric with the axis of the cam, means for limiting rotation of said cam to an angle of approximately whereby only one-half of the peripheral edge of said cam cooperates with said plunger, and dial means carried on the peripheral edge of the remaining portion of said cam.

4. A measuring gauge according to claim 3 wherein said dial means comprises an arcuate dial member covering the peripheral edge of that portion of said cam which does not cooperate with said plunger, said dial member having graduations formed on the outer face thereof.

5. In a measuring gauge, the combination of a housing, a circular cam mounted for rotation within said housing, a movable plunger carried by said housing and positioned to move radially of said cam, biasing means for urging said plunger into engagement with the peripheral edge of said cam, means for limiting rotation of said cam to approximately 180 whereby only one-half of said cam cooperates with said plunger, dial means carried on the peripheral edge of said cam which does not cooperate with said plunger, and a viewing window formed in said housing opposite the path of movement of said dial means.

6. In a measuring gauge, the combination of a housing, a pair of bearing screws mounted in threaded openings in opposite walls of said housing, a stub-shaft mounted in said housing and having the ends thereof journaled on the ends of said bearing screws, a circular cam mounted on said shaft in eccentric relation therewith, an adjusting knob rotatably mounted on one of said bearing screws outside of said housing, and a rigid driving member extending from said knob through an arcuate slot in said housing to effect rotation of said cam by said knob.

7. A measuring gauge according to claim 6 and including a friction clutch embodied in said knob and forming the driving connection between said knob and said driving member.

DONALD J. BAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 242,100 Barnes May 31, 1881 572,041 Willcox et a1. Nov. 24, 1896 697,400 Fawcett Apr. 8, 1902 839,943 Marsh June 1, 1907 1,414,484 Olsen May 2, 1922 1,499,729 Hanson July 1, 1924 1,786,325 Young Dec. 23, 1930 2,015,986 Aldeborgh et al Oct. 1, 1935 2,135,316 Whistler et al. Nov. 1, 1938 2,230,485 Dowdy et al Feb. 4, 1941 FOREIGN PATENTS Number Country Date 81,142 Switzerland May 16, 1919 604,660 Germany Oct. 25, 1934 

